Looks like there's no chance for Christina Aguilera and Jordan Bratman to work out their marriage issues ... now that X-Tina has officially filed for divorce.

According to the docs, that claim the couple separated on September 11th, Aguilera cited "irreconcilable differences" for the split.

There's also record of a prenup. Whew!! In the petition, Christina wants joint physical and legal custody of their 2-year-old son Max ... and doesn't want Bratman to collect child support down the road.

On Tuesday, our X17 photographers caught the couple spending the morning and early afternoon together, but Jordan left their home around 6pm to meet with his lawyer. Guess we now know why.

We'll see if they decide to play nice.